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View Full Version : Gaskets good or no.


Jersyboyy
05-03-2009, 01:04 AM
Guys with actual engine building experience please no tech article nut huggers thanks muchachos! :)

Here are the headgaskets im getting FPP-1144-061 (http://store.summitracing.com/partdetail.asp?part=FPP-1144-061)



Rear main seal (http://store.summitracing.com/partdetail.asp?part=FPP-2900) (because it doesnt come with the cam swap gasket kit, which together with a cam gasket kit is still cheaper than a full engine kit which basically adds head gaskets and rear main seal plus side is im using a performance rear main seal and saving a few bucks)


cam swap gasket set (http://store.summitracing.com/partdetail.asp?part=SUM-G2660)

Im basically am throwing in the rms and cam swap gaskets for ****s and giggles im really looking for postive feedback on the headgaskets before I hit buy.

Heres the reason behind getting such a thick gaskets btw.
Im looking at 10:99:1 compression with .061 headgaskets using a very good calculator.
(I punched in all the numbers using a .039 gasket to get the CR with 64 cc heads to match the compression info I got from srp then changed the head gasket thickness until it was spitting out the compression ratio I want with my 72cc heads)

I want to run pump gas dammit. Can you blame me? After all the hard work and time and effort and money I want to drive my damn car not trailor it...im using a comp nitrous 284 cam(hope to bleed off a little compression with that and its good for nitrous with the whole opening the exhaust valve earlier and all)
Maybe set the timing back slightly so I can street this car on the weekends without running 103 octane lol.

Suggestions advice agree disagree let me know fellas.
Thanks

1QWIKBIRD
05-03-2009, 08:48 AM
What kinda engine is the head gasket getting used on? 383? The bore size is pretty large 4.200, if its on a 4.155 bore or something then that's ok, but on a 4.030 bore you should try to find a gasket that more closely fits the bore. Did the calculator you used take into account the bore size of the gasket or did it simply ask for the compressed thickness?

I looked and couldn't find anything that thick in a smaller bore. Closest I could find as 0.051 for a 4.060 bore.

What piston are you using with a 72cc head that is requiring you to use such a thick gasket to get to 11:1?

Don't use that cam swap gasket set, its crap. Use this one piece oil pan gasket (or the correct one for your year block).
http://store.summitracing.com/partdetail.asp?part=FEL-OS34510T&autoview=sku. The one piece oil pan gasket pretty much eliminates leaks and makes swapping oil pans much easier.

and this

R.A.C.E. set
http://store.summitracing.com/partdetail.asp?autofilter=1&part=FPP-2702&N=700+4294925237+4294925236+115&autoview=sku

and for the intake get a set sized to match the openings on the heads you are using, fel-pro makes some nice ones and use RTV for the end seals.

And a good set of valve cover gaskets.

This is all the stuff I have on my 406. Use good hardware and if using an aftermarket oil pan, check it for fitment. I originally bought a hamburger pan and it sucked so bad I sold it and bought a moroso pan, which fit much better.

Chris
(not a pro, but a backyard DIY guy)

Jersyboyy
05-03-2009, 01:59 PM
These are the pistons http://www.jegs.com/i/SRP/867/140344/10002/-1#

the big bore was something I was worrying about, what exactly would be the down fall of using such a big bored gasket?

what about these http://store.summitracing.com/partdetail.asp?part=SCE-S11066&autoview=sku
Their smaller bore .062 thickness and are copper with no need for o ringing which makes then really tough?

1QWIKBIRD
05-03-2009, 02:45 PM
These are the pistons http://www.jegs.com/i/SRP/867/140344/10002/-1#

the big bore was something I was worrying about, what exactly would be the down fall of using such a big bored gasket?

Why the dome piston? To make up for the 72cc heads?

The overly large gasket bore will cause you to give up compression. If the bore is 4.030 and the gasket is at 4.200 you have 0.170 difference. Divide that by 2 and 0.085 would be the distance from the bore to the edge of the gasket. That is probably less than optimal. I don't know if that it would be problematic down the road or cause hot spots or other combustion issues, but if you haven't plunked down cash yet I'd talk to someone who does this for a living.

I don't know the overall combo, but if you have 72cc heads, why not run a good flat top pistion, with a more conventional 0.39 head gasket? Or have the heads milled to get the cc's down.

You mentioned being able to run on the street on pump gas. But the nitrous cam to bleed off cylinder pressure, the pulling timing to drive it on the street and the 0.061 head gasket are all crutches you would use to fix an existing problem?

A true 2 valve relief flat top with an 4.030 bore (-5cc for the valve reliefs), 3.750 stroke, 0.039 gasket (assumed gasket bore is equal to engine bore), with a 72cc chamber volume and a 0 deck will yield about 10.2+/- probably a tad less. Easily to do on pump gas without having to pull timing, run a nitrous cam (in a non nitrous appication I assume). If you milled the heads down to 68 cc you'd end up closer to 10.6 and still be good to go.

I'm confused on what parts you already have and what you are trying to accomplish? Best advice is consult a pro who does this for a living. The closer you get to the ragged edge the more important the details become and easier it is to waste $$$.

Good Luck
Chris

1QWIKBIRD
05-03-2009, 02:49 PM
These are the pistons http://www.jegs.com/i/SRP/867/140344/10002/-1#

the big bore was something I was worrying about, what exactly would be the down fall of using such a big bored gasket?

what about these http://store.summitracing.com/partdetail.asp?part=SCE-S11066&autoview=sku
Their smaller bore .062 thickness and are copper with no need for o ringing which makes then really tough?

Copper gaskets? You don't need to get involved with copper head gaskets.